Coating apparatus



Nov. 7, 1944. I R. B. LEECH I COATING APPARATUS Filed April 15, 1941 15 Sheets-Sheet l w M B m R Nov. 7, 1944. R. B. LEECH comma APPARATUS Filed April 15, 1941 13 Sheets-Sheet 2 c W a mllfi m L Q Q B a mo m ha a a a 2 Q 8n won m m g Q 5 mm 3 m M9 3 S w J ,/x/ Q w W? I JM/ n m Q N1 3 5 W N Ni 8% 9m mm, Q M, mum \WIWMY w l QM mmw Q r m m RM wQ W 0 L h\ R flmw nwm 7 m9 P w mn ME QM m km W mom 3m: Dm in w in m L wkw Hm QRW Em k QM Q 09w 5 Nov. 7,1944. R. B. LEECH COATING APPARATUS Filed April 15, 1941 13 Sheets-Sheet 4 3mm Bass 5. Lesa/2 15 Sheets-Sheet s R. B. LEECH COATING APPARATUS Filed April 15, 1941 Nova 7, 1944.

Nov. 7, 1944. R. B. LEECH 2,351,950

' COATINGIAPPAHATUS Filed April 15, 1941 13 Sheets-Sheet 6 Bass 5. Lesa/2 Nov. 7, 1944. R. a, LEECH COATING APPARATUS l3 Sheets-Sheet 8 Filed April 15, 1941 Russ .B. Leec z Nov. 7, 1944. R. B. LEECH 2,351,950 v GdA'IING hummus Filed April 15, 1941 15 Sheets-Sheet 9 Bass 5. Lcec/z Nov. 7, 1944. R. B. LEECH 2,361,950

COATING APPARATUS I Filed, April 15, 1941 13 Sheets-Sheet 10 grwsm/liob Russ B. Lecc/Z Sw amma uwl uw NM Wm M W an 33M KIM 1 m x w" H I Nov. 7, 1944. R. B. LEECH COATING APPARATUS Filed April 15, 1941 13 Sheets-Sheet 11 xmwFN m QE QREQ $52 m2 r mhlr amen MM Russ B. LGF'C/Y SEQ mg q Nov. 7, 1944. R. B. LEECH COATING APPARATUS Filed Ap ril 15, 1941 1a Sheets-Sheet 12 WML:

Nov. 7, 1944. R. B. LEECH comma APPARATUS Fi'led Aprillfi, 1941 13 Sheets-Sheet 13 Patented Nov. 7, 1944 2,361,950 COATING APPARATUS Russ B. Leech, Chicago, Ill., assignor to Standard Process Corporation, Chicago, 111., a corporation of Delaware Application April 15, 1941, Serial No. 388,ii94

(Cl. ill-33) 12 Claims.

This invention relates to an apparatus for' coating sheet or web surfaces and the lik and is more particularly concerned with apparatus for efficiently applying and distributing thermoplastic coating material upon moving sheet or web surfaces so as to provide thin uniform coatings having desired finish thereupon.

The present invention pertains mainly to improvements upon the apparatus described and claimed in the co-pending application of myself of spaced flexible coating smoothing blades for successively leveling quantities of coating mateand John D. Murray, Serial No. 260,188, filed March 3, 1939, now United States Letters Patent No. 2,249,089, granted July 15, 1941; and in the co-pending application of John D.-Murray, Serial 110,313,135, filed January 9, 1940, now United States Letters Patent No. 2,249,088, granted July 15, 1941.

It is a major object of the present invention to provide novel commercially practical apparatus for speedily and efficiently applying and'distributing thermoplastic material up n sheet or web surfaces to provide uniform thin coatings of desired finish thereupon.

A further object of the invention is to provide improved arrangements for depositing thermoplastic coating materia1 upon a sheet surface or the like, and especially improved coating deposit cylinder construction and novel heating. and heating control arrangements for maintaining the cylinder surface ata desired temperature. Specifically, adjustable thermostat controlled internal electrical heater units are provided for the deposit cylinder and doctor blade assemblies.

A further object of the invention is to provide.

novel coating smoothing and glazing blade constructions including a heated medial support for.

controlling the curvature and temperature of said blade and novel adjustments for the medial support and blades.

A further object of the invention is to provide a novel door assembly for swingably supporting a pluralityof coating smoothing blades in such a manner that the blades may be swung into and out of contact with the web surface being smoothed without the sharp edges of the blades shearing the web. Specifically. the door is so mounted as to provide straight line movement of the blades toward or away from the web surface during initial opening and final closing movements of the door so that during such movements, and while they are in contact with the web surface, the blades will be disposed normally to that surface.

A further object of the invention is to provide rial deposited upon a web surface or the like wherein the final blade contacting the surface is a glazing blade for providing a desired finish on the surface and is of greater flexibility than the other blades. Specifically, the glazing blade is appreciably thinner than the other blades.

A further object of the invention is to provide coating smoothing apparatus embodying novel adjustments for controlling the angle with which the web surface leaves the final smoothing or glazing blade.

A further object of the invention is to provide improved apparatus for coating webs with thermoplastic materia1 wherein novel arrangements are provided for pre-heating the web prior to coating and for maintaining the deposited coating material soft between deposit and smoothing.

stations.

A further object of the invention is to provide apparatus for coating paper webs and the like wherein a novel device for removing lint and like impurities from the web surface prior to coating is provided,

A further object of the invention is to provide novel flexible blade arrangements for leveling thermoplastic coating material deposited on a moving web surface wherein the blade may be pre-heated prior to normal operation of the coating apparatus.

A further object of the invention is to provide in a coating machine, novel coating hardening or setting roll arrangements having special internal cooling means, for chilling the coating before the coated web passes to a rewind stand.

Further objects of the invention will presently appear as the description proceeds in connection with the appended claims and the annexed drawings in which:

Figure 1 is a side elevation of the entire coating machine illustrating the manner in which the web is led from the supply reel to the coating apparatus and back to the rewind reel; V

Figure 2 is a front perspective view of the coating applying and smoothing apparatus.with the door upon which the smoothing blades are mounted swung open;

Figure 3 is a fragmentary View in section illus- [Figure is a section taken along line 5-5 of Figure 4 and illustrating further the electrical connections at the end of the deposit cylinder;

Figure 6 is a fragmentary view in section illustrating the end of the heater unit opposite to that shown in Figure 3;

Figure 7 is a section taken along line 'I! in Figure 6;

Figure 8 is a wiring diagram of the electrical system employed in heating the coating deposit roll; I

Figure 9 is an elevation of the doctor blade employed at the coating cylinder, especially illustrating the internal heating unit and manner in which the thermostat switch is mounted;

Figure 10 is a section taken through a portion of the doctor blade illustrating its manner of assembly and the mounting of the heating unit therein;

Figure 11 is a front elevation of the glazing door with the outer hinged panels removed to illustrate the blade supports and adjustments. The blades themselves and many of the control knobs are omitted for the sake of clarity.

Figure 12 is a side elevation of the door of Figure 9 illustrating-mainly the medial support bar adjustment controls.

Figure 13 is a top view of the glazing door partly broken" away to show the special hinge arrangement for insuring straight line initial opening and closing movement.

Figure 14 is a side elevation partly cut away' and partly in section illustrating in enlarged detail the blade supports and adjustments.

Figure 15 is an enlarged section taken along line l5-I5 in Figure 11.

Figure 16 is a fragmentary end view illustrating the slidable support employed at each end of each blade.

Figure 17 is a section taken along lines l'l-Il of Figure 15 illustrating the mechanism for simultaneously adjusting both ends of the blade and medial support.

Figure 18 is a fragmentary plan view in section along lines l8l8 of Figure 15 illustrating the manner in which theflexible blade holder is supported at each end.

Figure 19 is a front elevation, partly in section, ofthe swingable roll for determining the angle with which the web leaves the final or glazing blade edge.

Figure 20 is a front elevation. partly in section illustrating the coating cooling cylinder drive and fluid circulating system of Figure 1.

Figure 21 is a section taken along lines 2l--2i of Figure 20 illustrating further drive arrangements for the cooling roll.

Figure 22 is a wiring diagram illustrating especially the manner in which each of the heated coating apparatus units of Figure 1 -is energized.

'of Figure 24. L

Figure 26 is an end elevation of the blade mount of Figure 24.

Figure 27 is a diagrammatic representation of a further embodiment of the invention wherein the web is backed by an endless belt at the smoothing and glazing station.

Like reference characters indicate like parts throughout the several views.

Referring to Figure 1, the coatingmachine comprises an inverted U-shaped frame consisting of legs II and i2 connected by a bridge l3. Leg ll serves as a reel stand for the web supply reel and the reel for rewinding the coated web; and

' leg l2 supports the coating applying and smooth ing apparatus. Web S may be made of paper, fabric or any desired flexible sheet, material and the illustrated machine is especially designed for coating paper or similar porous surface webs.

Above leg l2 of the machine, extends a suitable hood in (Figure 2) connected to an exhaust system for collecting and exhausting fumes and vapors escaping from the coating apparatus.

A paper supply reel I4 upon which the web S to be coated is wound is rotatably mounted in a suitable manner adjacent the lower forward end of leg II and provided with a brake mechanism of well-known construction actuated by knob l5 for controlling its delivery speed.

Above reel l4, web S travels over an idly mounted guide roll IS, a second idly mounted guide roll H at the top of leg ii and then forms a downward loop between roll I1 and adjacent idler roll i8. Supported within this loop is a weighted roll l9 whose opposite ends are mounted in blocks 2| supported for slidable vertical movementin suitable guides 2|, on the opposite sides of leg I i. Weighted roll l9 assists in pulling web S off the supply reel, maintains the loop between rolls I! and I8 to take care of unstable feed conditions and helps keep the web undereven tension during its path from the leg II to the coating apparatus on leg l2. Above and below blocks 2| are provided stops 22 and 23,

respectively, for limiting vertical movement of roll- I9.

The opposite ends of idler roll iii are rotatable in adjustably mounted blocks 20 at opposite sides .of leg II and these blocks may be vertically displaced by actuation of knobs 24 threadedly connected thereto. This adjustment changes the size of the web loop and the web direction along bridge i3.

' From roll l8, web S passes along the under side of bridge I3 to the coating apparatus on leg 12 which will be later described in detail herein and, after being coated, returns along bridge l3 to pass over a driven rotatable roll 25 supported across the upper rear corner of arm II. Web S passes from roll 25 downwardly directly to a driven rewind reel 26 supported at the lower rear corner of arm ll.

Roll 25 is connected at one end by means of suitable gearing and coupling mechanism contained in the housing indicated at 21 to an elongated drive shaft 28 extending behind bridge i3 and driven by an electric motor 334. (Figure 22) adjacent the bottom of leg l2 as will later be described. Since the specific nature of this gearing and coupling mechanism is not an essential part of the present invention, further description of Coating apparatus At the upper inner corner of leg I 2 and substantially horizontally aligned with roll IS, an adjustable rotatable idler roll 36 has its opposite ends supported on vertically adjustable blocks controlled by knobs 31. Leg I2 is provided with hinged rear doors |2' which are suitably apertured to permit passage of the web and which help maintain desired temperature conditions at the coating and smoothing station as will presently appear. v

Substantially "directly below roll 36 is a rotatable guide roll 38. A second rotatable guide roll 39 is positioned in horizontal alignment with roll 38 and the web passes beneath these guide rolls in a horizontal path with the surface to be coated facing downwardly. Guide rolls 38 and 39 have their opposite end shafts 38 and 39' mounted in suitable elongated guides as shown in Figure 1 and along. which they may be displaced by actuation of suitable adjustment screws 40 and 40' to determine the linear path of the web as desired.

Between rolls 38 and 39 is provided a coating material deposit pass comprising a coating deposit cylinder 4| and a vertically aligned impression cylinder 42 which is preferably surfaced with rubber or some other resilient material.

Cylinder 4| is driven at a Peripheral speed equal web as it passes between cylinders 4| and 42,

means for vertically adjustably displacing cylinder 42 are provided. End shafts 42 of cylinder 42 are rotatably supported in blocks 43 vertizally slidably mounted at opposite sides of leg I Each block 43 is connected by an arm 44 to a boss 45 and the bosses are interconnected by a rigid transverse bar 44'. An externally threaded adjustment shaft 46 has its lower reduced end rotatably disposed within boss 45 at each side of leg l2. Each shaft 46 is provided with rigid collars 46 above and below the boss to prevent axial displacement and. to support the boss on the shaft.

At itsupper end, each shaft 46 is received within the internally threaded coupling sleeve 41 rigid with a bevel gear 46. Bevel gears 49 at opposite ends of a rotatable transverse shaft mesh with gears 48. At one end, shaft 5| has keyed thereto ahand wheel 52, of large diameter to gain suificient leverage for lifting the heavy cylinder 42. Upon rotation of hand wheel 52, both shafts 46 are rotated and axially displaced and both ends of cylinder 42 will therefore lie-simultaneously vertically displaced. and the pressure of cylinder 42 upon the web can thus be regulated to a desired degree. 7

Any other suitable means for vertically adjusting cylinder 42 with its axis parallel to cylinder 4| may be employed since the specific details of such mechanism do not comprise an essential part of the present invention and further description of the same is unnecessary.

The lower periphery of coating deposit cylinder 4| dips into and below the level of a bath of melted thermoplastlc'coating material in a pan or container '53 provided with a central overflow spout 54.

Container 53 is'mounted upon an adjustable support having depending end posts 55 slidable upon suitable guides at opposite sides of leg l2.

'Each of these posts 55 is provided with rack teeth 55 for engaging gears 51 at opposite ends of a rotatable shaft 58 which extends between opposite side walls of leg l2 and terminates at one end outside the leg in an enlarged external gear 59 meshed with 'a rotatable worm 6| on a control handle shaft 52. As control handle shaft 62 is rotated, pan 53 is displaced vertically to regulate the level of the material therein with respect to the coating deposit cylinder or to displace the pan far enough below the coating deposit cylinder so that both are accessible for cleaning or like purposes.

coatin deposit cylinder coating deposit'surface of cylinder 4| is therefore believed to be unnecessary to understand the present invention.

Special means are provided for internally heating cylinder 4| as will now be described and as are illustrated in Figures 3-8, inclusive.

Cylinder 4| is hollow and provided at one end with a suitable drive mechanism (not shown) for rotating it at constant speed. At its other 'end cylinder 4| has a hollow coaxial cylindrical end shaft 63 of smaller diameter removably secured thereto as by cap screws 64 passing through an integral flange 65 seated in an internal shoulder 65' at the end of cylinder 4|.

At its outer end, shaft 63 has its external diameter reduced, as shown in Figure 3, to pass through and be rotatably supported by a suitable roller bearing assembly arranged in a suitsulating material carrying a, pair of spaced hollow electrical binding posts 89 and II disposedat either side of a. central aperture 12. Plug 68 terminates flush with the outer edge of shaft 63 and is non-rotatably secured therein as by set screw 10. v

Surrounding the outer end of shaft 53 is an annular sleeve 13 of insulating material provided intermediate its ends with a raised shouldered portion upon which is press fitted a.- ring 14 of electrical insulating material separating two metal rings I5 and 16 likewise press fitted upon the sleeve at opposite sides of. the shouldered portion. 7

Rings 14, 15 and 16 are traversed by parallel longitudinal electrical binding posts 11 and 18 which extend beyond the outer end of shaft 53 through an end plate 19 of insulating material. Post 11 is insulated from ring I5 by a sleeve 8| of suitable insulating material, and from ring 16 by a similar sleeve 62-. Anannular disc of insulating material 83, apertured to fit over the inner ends of posts 11 and 18 insulates terminal nuts on the posts from ring 16. Post 18 is preferably in threaded engagement with ring 15, but is insulated from ring 16 by a sleeve 84 of suitable insulating material.

The outer end of hollow post 69 abuts against a nut 85 disposed in a suitable aperture in plate 19 and mounted upon an intermediate threaded portion of a bolt 86 passing through an insulating end block 81. The elongated inner tip 80 of bolt 86 is snugly received within hollow post 59. As shown in Figures 3 and 4, a thin metal strap 88, disposed between plate 19 and block 81, connects the outer end of binding post 11 with bolt 96 thus providing an electrical connection between binding posts 69 and 11.

The outer end of hollow post 1I abuts against a nut 89 disposed in a suitable aperture in plate I9 and mounted upon an intermediate threaded portion of a bolt 9| seated in block 81. The inher tip 90 of bolt 9| is elongated to fit snugly within hollow post 1!. Bolt 9I and the outer end of binding post H are interconnected by a thin metal strap 92 similar to strap 80 thus providing an electrical connection between binding posts 1| and 1a.

A thermostat switch box 93 is rigidly mounted.

upon block 81 at the extreme outer end of shaft As shown in Figure 5, disc 83, rings 14, 15 and 16, plate 19 and block 81 are longitudinally traversed by a second pair of diametrically spaced Referring to Figure 8, switch box 93 contains I a pair of metal bus plates 99 and MI and a switch arm. I02 mounted on a fibre block I03. Anadjustable screw I00, preferably actuated by an external knob I00 (Figure 4) determines the initial open position of arm I02. Bus IOI is connected by a cable I04 to post 94 which'in turn is threaded in ring 16, as above-described. Bus

99 is connected by a cable I05 to post 11 and] from thence by means of strap 88 and binding post 89 to a cable I06 leading to one end of a heating element I01 disposed within the coating deposit cylinder. The other end of element I01 is connected by a cable I08 to post II whose outer end is connected by strap 92 to post 18 which in turnis threaded in ring 15. Thus a complete electrical circuit within the coating deposit roll adapted to be connected to a source of current through rings 15 and 16 is provided.

.A cylindrical casting I09, preferably of aluminum, is snugly but removably fitted within cylinder 4I and provided with an integral end extension-H0 projecting a substantial distance within shaft 53. Heater element I01 is housed in a flexible rod disposed in a. U-shaped passage within casting I09 with its medial bent portion adjacent the drive endof cylinder 4] (Figure 6) and with its closely adjacent terminal legs projecting beyond extension IIO to be connected to cables I06 and I08 respectively (Figure 3).

As illustrated in Figures 6 and '1, casting I09 is grooved at opposite sides to accommodate a pair of flat metal straps III and II I' disposed at opposite sides or heater element I01 and clamped thereto by a bolt I01 threaded in strap III. Casting I09 may be removed as a unit from cylinder 4| by removal of screws 64 for speedy replacement of a new heater unit should element I01 burn out or'be of insufficient capacity for a desired purpose.

Casting I 09 and extension IIO are centrally apertured at M2 to receive a hollow tube II3 housing a capillary tube II 4 extending between a suitable thermometer bulb imbedded within casting I09 and a suitable pressure responsive element (not shown) connected to switch arm I02.

Electrical energy is supplied to heater element I01 during rotation of cylinder M by brushes I I5 and H6 bearing on rings 15 and 16 respectively. A rigid brush holder support stud I I1 is secured, as by nut IN, to le I2 from which it projects outwardly parallel to the deposit cylinder axis. An insulating sleeve H8 is made rigid with stud I I1 and supports a pair of identical spaced brush holders H9 and I20.

Brush holder II9, as shown in Figure 4, is bifurcated at one end to surround sleeve H8 and is clamped thereto as by bolt assembly I22. Ad-

- jacent its other end, holder H9 is socketed to slidably receive brush I I5 which is resiliently held against ring 15 as by a fiat steel spring I23.

Brush holder H9 is provided with a binding post I24 to which is secured a short flexible cable I25 leading to brush II 5 and a cable I26 from one side of the line. Brush'l I6 is similarly connected to the other line cable I21.

Brush holders H9 and I20 are rotatably adjustable about sleeve II8 upon loosening of bolts I22 and may be secured in selected adjusted postion by tightening the bolts.

The entire end assembly of cylinder 4| projecting outwardly of leg I2, including the brush holders and switch box 93, is protected by a suitable housing I28 whichis rigid with leg I2 and is provided with an openable door I29 hinged at I30 to permit access to its interior.

Doctor blade assembly Referring to Figures 9 and 10, the doctor blade comprises a, flexible spring steel blade I30, of the type usually employed in intaglio printing apparatus, having a longitudinal edge clamped between opposed metal bars I3I and I32 comprising a stiffening holder therefor. Bars I3I and I32 are secured together by screws I33 which pass through enlarged blade apertures I 30 and are tightened only enough to hold the blade against accidental displacement. This loose clamping arrangement together with the enlarged blade apertures permits free expansion of the blade when heated without localized distortion or warping.

Bars I3I and I32, with blade I 30 therebetween, are mounted in a shouldered portion of a main doctor blade support I34. A fiat plate I35, also seated in a shoulder on support I34, is secured rigidly to the latter as by cap screws I36 and extends along the outer surface of bar I32. Suitable set screws I31 on plate I35 retain the doctor blade' holder on its support.

Beneath plate I 35 and inwardly of the blade holder, support I34 is provided with longitudinal surface grooves generally forming an elongated oval I38 suitably enlarged at its ends at I38 and containing a, heater rod I39 having reversely bent ends lying in said enlarged groove portions I38 to facilitate its insertion and removal and attachment of current carrying wires thereto.

Heater rod I39 is clamped firmly inits groove by engagement with the interior surface of plate I35 as shown in Figure 10.

Doctor blade support I34 is provided at one end with a stub shaft I46 slidably and rotatably supported in and extending through a suitable bearing bracket I46 rigid with leg I2. Shaft I40 has removably secured thereto a bifurcated terminal member I4I carryin a crank pin I4I' rotatably connected to one end of a reciprocating crank arm I42. Crank arm I42 may be reciprocated by any suitable mechanism such as that commonly employed for reciprocating doctor blades in printing apparatus and further description of the same is unnecessary to understand the invention.

Doctor blade support I34 is provided at its opposite end with a stub shaft I43 having a tubular end portion I43 slidably and rotatably supported in a suitable bearing bracket I44 rigid with leg I2. Shaft I43 telescopes a solid shaft I45 extending from a rigid bracket portion I46.

Shaft I43 and shaft I45 are squared or otherwise shaped to be slidably but nonrotatably interconnected, and shaft I45 provides an additional slidable support for that end of the doctor blade support. I

Shaft I45 is formed with an intermediate reduced portion rotatably supported on a rigid bracket I46, and outwardly of bracket I46 carries a gear I41 secured thereto as by key I48. At its inner side, bracket I46 carries an annular thrust member I49 against which the end of shaft I43 abuts during reciprocation of the doctor blade. 4

Referring to Figure 1, gear I41 meshes with a worm I56 on acontrolshaft I rotatably supported in suitable bearings on leg I2 and provided with a handle I5I'.

imbedded in holder I34 and connected to said switch mechanism by a flexible capillary tube I53. Since tube I53 lies mainly along the axis of shaft I45. it will not'be appreciably affected by reciprocation or rotative adjustment of the doctor blade holder.

The switch mechanism in box I52 is adjustabl to obtain a desired temperature 'of blade I38, preferably equal to the surface temperature of cylinder 4I.

Constant level fountain Fluid thermoplastic coating material is fed into container 53 by a supply pipe I54 through which the melted coating material is pumped from a combined melting and storage tank I54 by means of a suitable pump I55 located-in a fluid tight compartment in the tank as shown in Figure 1. The pump shaft is provided with a pulley III (not shown). Solid unmelted coating material is placed in an upper tank chamber I56 whose bottom comprises a series of heated bars effectively forming an apertured grating or grill I51 which melts the material and permits it to flow downwardly to :be collected in tank I54. Pump I55 is operated to deliver coating material to container 53 at the same rate it is used, or at a slightly greater rate to provide a continuous. circulation of said material, and excess coating material overflows through spout 54 back into the tank.

Glazing door When web S leavesthe coating deposit station, its coated surface contains a uniform pattern of localized, closely adjacent separate ridges or mounds of thermoplastic material-which must be leveled to provide a continuous uniform coating over the web surface. This levelling apparatus is illustrated best in Figures 1, 2 and 11-18.

Referring to Figures 1, 2 and 14, a series of spaced, parallel, vertically aligned rolls I58,' I59, I6I and I62 are mounted substantially directly above roll 39. Rolls I58, I59 and I6I are simply elongated polished cylinders mounted for free rotation about fixed axes on the frame. Roll I62 is also a polished cylinder but has a special swingable mounting later to be described. These rolls effectively provide a guide for backing web S during coating, leveling and smoothing operations.

Referring to Figures 2 and 11, a glazing door generally designated as I63 comprises a hollow rectangular frame I64 from whose inner edges project top and bottom walls I65 and I66 and side walls I61 and I68, preferably integral therewith.

Leg I2 is provided at one front side edge with upper and lower bearing blocks I69 and HI, respectively, through which extend a rotatable vertical shaft I12. Horizontal door support arms I13 and I14 are non-rotatably secured as by pins I13 and I14 to shaft I12 above blocks I69 and Ill respectively as illustrated in Figure 11'.

Blocks I69 and HI thus support the entire weight of the door for swinging movement about the axis of shaft I12. At its free end, upper arm I13 is provided with a hollow boss I15 surrounding a rotatable pivot pin I16 upstanding from wall I65. The free end of lower arm I14 is provided with a hollow boss I11 fitting over a rotatable pivot pin I18 vertically aligned with pin I16 and projecting downwardly from wall I66.

In this manner the whole glazing door I63 is rockably supported upon a rigid support made up of arms I13 and I14 interconnected by shaft I12; and that rigid support in turn is rotatably supported upon leg I2. v

Special linkage for controlling and limiting rocking movement of door I63 about pivots I16 and I18 is also provided.

Intermediate its ends, arm I14 is formed with a hollow |boss I19 through which extends a rotatable pin I8I upon whose opposite ends are nonrotatably secured levers I82 and I83 as by pins Lever I82 terminates in a boss I84 provided with an elongated aperture I84 slidably and rotatably fitting over a post I65 projecting downwardly from wall I66. Aperture I84 provides a lost motion connection between lever I82 and post I85 for a purpose to be later described.

- The outer end oi arm I83 has rigidly afllxed driven by meansof a suitable motor driven belt 15 thereto a downwardly projecting Post I 86 having a cylindrical roller shank adapted to travel along an arcuate cam recess I81 provided in a plate I98 bolted to the frame below the door. Post I86'terminates in an enlarged button I89 larger than the widthof cam slot I81 to prevent the post from being accidentally withdrawn from the cam slot.

Referring to Figure 13, as door I63 is swung open in a counterclockwise direction about the axis of shaft I12, the common axis of pivots I16 and I18 swings in an arcuate path about the axis of shaft I12 but door I63, by operation of cam slot I81 and levers I92 and IE9, is caused to simultaneously and compensatively rotate in a clockwise direction about the common axis of pivots 516 and I18 so as to maintain door I93 substantially parallel to the web and give it a substantial straight line movement away from its full line closed position to the partly open position indicated by dotted lines A in Figure 13.

After door I63 has moved normally to the web for a distance of about three inches, post I86 will have reached a portion of cam slot I81 where it is no longer effective to cause further rocking movement of the door and door I63 will merely swing outwardly along with support arms I19 and I16, until fullyopen position E (Figure 13) is reached, without further clockwise rotation. Post I86 remains in slot H81 and retains door I63 angularly disposed with respect to the support arms. I

The reverse operation takes place when the door is closed. The whole assembly swings back about the axis of shaft I12 as a pivot until the dotted line position A of Figure 13 is reached, about three inches away from the web. At this point, post I86 reaches the portion of cam slot I81 where it is again effective to control rotation of .the door about the common axis oi pivots I16 and I18 and, upon further elosingmovement, the door is simultaneously rocked about that axis in a counterclockwise direction to maintain it parallel to the web until it reaches the closed full line position of Figure 13. The purpose of this special movement of door I63 will be later described.

As shown in Figure 13, door I63 is provided with a central vertical bridge I9l rigid therewith and provided at opposite side edges with piano hinges I92 for supporting identical cover members or panels I93 which are swingable to an open position when the door I93 is closed as shown in Figure 13 for a purpose to be later described. As shown in Figure 1 each cover I93 is provided along its outer edge with an elongated opening I90 for a purpose later to be described. Door I63 is provided with a central knob I95 (see Figures -1 and 13) for pullingit open, and each closure member I93 is provided with an individual door knob I94 (see Figure 13). Referring to Figure 2, I a pivoted latch I900. is adapted to fit over a suitable latch pin I90 on frame I to lock the door.

in closed position.

' Smoothing and glazing apparatus Inner walls I95-I60 of door- I63 provide a boxlike frame for supporting the coating smoothing and glazing blades of the invention. Referring first to Figures 1 and 14, web 8 during its travel upwardly from roll 39 is contacted between alternate guide rolls by a succession of flexible Blades I98-I99 are thin, flexible and springy, preferably being made of a good grade of steel, and have their free web engaging edges ground, honed or otherwise sharpened to provide a straight, smooth, true sharp beveled edge at c (Figure 15). Blade I99 is preferably thinner and more flexible than the other blades for reasons which will presently appear.

All of the blades are identically supported and adjusted and details of the adjustable support for a representative blade I91 will now be de scribed.

Referring to Figures 15-18, one longitudinal edge of blade I91 is clamped in a blade holder comprising a pair of long, rigid flat bars 205 and 206 secured together as by screws 201. Blade I91 is provided with enlarged apertures l91 through which project rigid dowel pins 200 upstanding from bar 206. Screws 201 are tightened only to such degree as to clamp the blade edge relatively loosely but yet firmly enough to prevent accidental displacement. This manner of loosely clamping the blade permits unrestricted expansion of the blade when heated and thereby prevents warping and localized distortion and is substantially the same as that described and claimed in Serial No. 313,135, above-identified, to which reference is hereby made for further detail. If desired, blade I91 may be heat insulated from bars 205 and 206 by suitable interposed liner strips of asbestos or the like.

At opposite ends, the blade holder is supported upon a pair of identical plates 209 rigidly secured to the ends of bar 206 as by bolts 2I I (Figure 18). Preferably suitable asbestos heat insulation linings are inserted between lates 209 and bars 206. Bolts 2 are tightened securely and do not interfere with the above-described loose support for the blade. Each plate 209 has its outer edge slidably disposed within a guide groove 2I2 formed on the surface of a block 2I3 which in turn is recessed at 2 along its bottom surface to fit over a rectangular guide bar 2 I 5 rigidly secured to the adjacent side wall I88 of the glazing door as 7 by bolts 2I6.

site sides of this bifurcated arm are embraced by collars 223 and 224 rigid with a manual knob 225 which is rotatable upon stud 2I9 by reason of threaded engagement therewith, as illustrated in Figure 15. Upon rotation of knobs 225, blade support members 209 will be shifted bodily along guide 2I2. Thus each end of blade I91 is identically and independently adjustable.

Medial 'support bar 202 is parallel to blade I91 and preferably comprises a cylindrical metal tube whose opposite. ends are internally shouldered to flt over hollow posts 220 rigid with blocks 2I9 at opposite walls I01 and I89 (Figure 17). Bar 202 is non-rotatably secured to posts 226 as by set screws 221. Posts 228 are preferably made of heat insulating material to prevent heat from being conducted away from bar 202 to block 2I3 and the other metallic parts of the machine frame. Bar 202 is preferably provided with a suitable internal electrical heating unit similar to that described above within coating cylinder 0i and since this heating unit may be of any desired time it will not be described in detail. Posts 226 are centrally apertured at 230 in alignment with ccoperating passages 23. inblocks 2|3 for leading current conducting wires to the heating unit.

By the above described construction, blade I91 as by pin 2 to a rotatable shaft 232. Shaft 232 extends parallel to bar 292 and has one end rotatably supported in a suitable bearing plug 233 fixed in an aperture in wall I68.

At its other end (see Figures 2 and 11) shaft 232 is provided with a fixed gear 239 engaging rack teeth 228 on slide block 2I3 on wall I61 and extends through a suitable removable bearing assembly 234 in wall I61 and has rigidly secured thereto, as by pin 235, a pinion 236. Pinion 236 (Figures 2 and 12) meshes with a worm 231 rigid with the inner end of a shaft 238'rotatably supported in a bearing member 239 and secured within an aperture in frame I64. A control handle MI is fastened to the outer end of shaft 238.

Rotation of handle 2 will rotate shaft 232 and; by reason of gears 229 and 230 meshing with racks 228 on opposed block 2I3, will cause simul-.

taneous displacement of blocks 2I3 along guide bars 2l5. The above-described adjustment shifts blade I91 and bar 202 as a unit substantially perpendicularly toward or away from web S.

Each of the other flexible blades I96, I98 and I99 is mounted in the same manner as blade I91 above-described, and provided at opposite ends with individual blade end adjustment control knobs (Figure 14) 242, 243 and 244, respectively, identical with. knob 225. This construction is also illustrated in Figure 11, where the blades,

door panels and most of the knobs have been eliminated for the sake of clarity, but wherein it is clear that duplicate lugs 2! are provided on each opposed guide block 2I3 and these lugs are designed to carry knobs 242, 243 and 244 in the same manner as knob 225. v As shown in Figure 14, even when door panels I93 are closed, knobs 225, 242, 243 and 244 may be reached by the fingers through openings I99 for adjustment purposes.

Manually controlled knobs 245, 246 and 241 are provided for actuating shafts 248, 249 and 251, respectively, to simultaneously adjust blade I96 and its'associated medial support bar 2IlI, blade I98 and its associated support 203 and blade I 99' and its associated support bar 294, respectively. asunits, in the same manner that blade I91 and bar 292 are adjusted as aunit as above-described.

Since each flexible blade and support bar unit is substantially identical except. as to flexibility of the blades as will later be described in detail, further description of the same is not necessary.

When door I63 is in closed position each of the flexible smoothing blades contacts 'the web S over a substantial end area as illustrated in the case of blade I91 in Figure 15. Under pressure of web S, blade I91 is bent from the dotted line position in Figure 15 to the full line position, wherein it is medially hacked or supported by'the underlying arcuate surface of bar 292. Blade I91 closely contacts the arcuate surface bar 282 over an intermediate area H, and then projects beyond such area of contact with the bar to provide a free flexible end area b-c about one-quarter to one-half an lnch along the blade, and then terminates in a free straight smooth edge cover which thecoated surface to be smoothed is drawn at a slight angle as it leaves the blade.

As shown in Figure 15, the coated web surface contacts the blade over a portion of area a'-b as and web surface illustrated at Figure 15 and above-described is substantially the same for the three lower blades I96, I91 and I 98 which will hereafter be called smoothing blades. No attempt is made to measurably control or determine the angle at which web S leaves these blades except, of course, to insure that'there is at least a slight angle. Upper blade I99, however, is followed by roller I62 (Figures 2 and 14) which is adjustable to accurately determine and set the slight angle with which the coated web surface leaves the blade and thereby determines the glaze -or finish finally imparted to the coating. Blade I99. serves both to finally smooth the coating and determine its finish and will be hereinafter called the glazing blade.

Since the three lower blades I96-I98 perform the heavier duty work of levelling the deposited quantities of coating material, they are preferably thicker and less flexible than the glazing blade. For smoothing Liquafilm No. 111 which has been deposited upon a paper surface traveling. at 200 feet per minute, I have successfully used blades at I96, I91 and I98 which were seven-thousandths of an inch thick, while blade I99 was only four-thousandths of an inch thick.

The adjustable support for roller I62 is best illustrated in Figures 2 and 19. The opposite ends of roller I62, which is a hollow cylindrical tube, are rotatably supported by means of bearing assemblies 248 and 249 upon a solid-shaft 25I which extends centrally therethrough and whose opposite ends are secured, as by pins 252 and 253, in apertured bosses at the ends of a pair of parallel arms 254 and 255. Arms 254 and 255 are provided, at their other ends with collars 256 and 251, respectively, through which pass a solid shaft 258 Whose opposite ends are supported in suitable bearings upon opposite side walls of leg I2 and which is parallel to roll I62. are non-rotatably secured to shaft 258 as by pins 259 and 26 I, respectively.

Shaft 258 projects through the side of leg I 2 adjacent hand wheel 52 and has secured thereto, as by set screw 262, an enlarged gear 263; Gear 263 meshes with a worm 264 keyed or otherwise I non-rotatably secured upon a control handle shaft 265 which is rotatably supported in suitable bosses 266 and 261 on the outer side of leg I2. A knob 268 is fixed on shaft 265 for manual control of this adjustment. Rotation of knob 268 (Figures 2 and 14) causes shaft258 to be rotated about its axis and the roller 162 is bodily swung to vary the angle with which the web leaves the terminal edge of blade I99.

Referring to Figures 11 and 13, bridge I9I is provided adjacent each blade and medial sup port bar unit with separate thermostat switch areas a-b andb-c and the areas of contact Collars 256 and 251 

